Device for rendering visible acoustic vibrations

ABSTRACT

The invention relates to a device for rendering visible acoustic vibrations, in which a fluid medium held on a foundation is caused to execute wave notions with the help of a movable wall or wall section, and in which the wave motions thus engendered are rendered optically visible.

l 0 mum rm nited State: 1111 3,818,137 swim I -Em Rage l A f 1 June 18,1974 [54] DEVICE FOR RENDERING VISIBLE 3,234,847 2/1966 Williams 1.84/464 3,547,520 12/1970 Lee et a1 v 350/161 ACOUSTIC VIBRATIONS3,580,126 5/1971 Forkner .1 84/464 [76] I r: fr g c/o lnstitut f.3,604,852 9/1971 Weintraub 84/464 wissenschaftl, Foto afie, Turmstrasse4, 705g/rwinnenden FOREIGN PATENTS OR APPLICATIONS Germany 1,071,6936/1967 Great Britain ..\l79/l VS 22 Fl (1: l 1, 1971 1 1 6 y PrimaryExaminer1(athleen H. Claffy 1 1 pp 158,741 Assistant Examiner-Douglas W.Olms [52] US. Cl 179/1 VS [57 ABSTRACT [51] Int. C1. G101 1/00 Th I d fd [58] r1618 61 Search 179/1 vs; 350/l6l;-84/464 7 9 ermg e acousticvlbratlons, 1n WhlCh a fluid medlum held on a foundation is caused toexecute wave notions with the [56] References Cited help of a movablewall or wall sectlon, and in WhlCh UNITED STATES PATENTS the wavemotions thus engendered are rendered opti- 2,879,337 3/1959 R615 350/161ally isib]e 3,048,075 8/1962 Wright.... 3,163,078 12/1964 Elliott 84/46425 Claims, 9 Drawing Figures 6 ,//LENS SYSTEM MULTICOLOR PLATEPATENTEDJHH 1 m4 3.8 18137 SHEET 1 0F 3 SCREEN ,/LENS SYSTEM M ULTICOLOR PLATE VIBFCQSITLOR I 3 57 A f1 59 i T i l FOUNDATION till y 5PLASTIC CYLINDER INVENTOR. YMANFKED P i /-\6 E PATEN'IEDJHN 1 w smalls"!SHEET 2 OF 3 Z;- 26 RINGS-190 q Hg 4 I VIBRATOR i 27 H946: LOUD SPEAKERall 30 Fig. 4C LOUD SPEAKER scum SOURCE K DYNAMIC M coMPREssoR*AMPLIFIER *AMPLIFIER V 450 52 4812 5 54 g 9;] 3 49b 49a SPEAKERSINVENTOR.

MAMFRED P. KAG-E BY PATENTEDJUNIBBH (818,137

sum 3 0F 3 FIG. 7

DEVICE FOR RENDERING VISIBLE ACOUSTIC VIBRATIONS The object of thepresent invention consists in making an arrangement with whose helpacoustigvibrations 5 tramsmitting medium consists of a material which is'transpare nt or which reflects the light in the manner of a mirror,there being on one side of the foundation a first optical groupconsisting of a light-source, e.g., a so-called xenonlamp, andparticularly a so-called HBI lamp, and a reproduci ng optical systemserving to reproduce a light-spot originating from the light source and,on one side of the foundation, there is a second optical groupconsisting of a multicoloured patterned viewing plate with a surfacewhich has a grid ora network of lines at right angles to each other,preferably made of glass, in the region of the focal point of thereproducingoptigaLsystem, and also consisting of an objective arrangedbehind the viewing-plate when, seen in the direction of the beam oflight, said objective serving to project the beam coming from thelight-spots on the multicoloured viewing-plate on to a screen.

The arrangement according to the invention enables 3O a s t onishingopticaleffects to be achieved with relatively' simple means. If, forexample with the help of loudspeakers, continuous successive sounds aregenerated, such as occur, for example, when music is played, mulgr]Quredimagqsm x "5866 device, the shape of the individual components,

and the intensity and shading of the colours being clearly seen, even bythe lay observer, to be dependent on the pitch and intensity of theindividual sounds. The individual vibratory shapes are repeatable, i.e.,they are each associated with only one sound. Acomplete vibration picture is made up of different figure-fields, of which each can have adifferent generative basis; the foundation may vibrate in resonsance tothe appropriate sound, or the resonsance frequency of the membrane mayfeed back, or eddies may form within the fluid, absorbing the soundfrequency.

Embodiments of the subject-matter of the invention are shown by way ofexample in the drawing, which shows:

FIG. ll: an arrangement according to the invention, in diagrammatic sideelevation;

FIG. 2: a diagrammtic side elevation of a detail of a variant of thearrangement in FIG. I, on a larger scale FIG. 3: a plan view of theviewing-plate of the arrangement in FlG'l;

FIG. 4a: a side elevation of a possibility of generating the wavemotions in the transmitting medium;

FIG. 41): another side elevation of another possibility of generatingthe wave motions;

FIG. 4c: another side elevation of another possibility of generating thewave motions;

be sfiesnmonwthe screen of the FIG. 5: a disgram of a further detail ofthe arrange- FIG. 7: a further modification of the invention indiagrammatic side elevation.

The invention proceeds from the interference tests described by Pohl inhis Einfuhrung in die Physik, vol. 1, Berlin, 1940, in which a fluidmedium was caused to vibrate by a movable wall, e.g., a rod or the like,giving rise to circular radiating wave motions which were projected, sothat a whole auditorium could observe these movements. The arrangementaccording to the invention contains as essential components alight-source ll, a reproducing optical system 2, a foundation 3 for thefluid transmitting medium 4, a mu]- ticoloured viewing-plate 5 and alens system 6 with which is associated a visual screen 7. According tothe invention, the foundation containing the medium 3 consists of amedium which is transparent, or reflects the light in the manner of amirror, and on one side of the foundation there is provided the lightsource 1 and the producing optical system serving to generate areproduction of a light-spot originating from the light source, theseparts forming a first optical group, while a second optical group islikewise provided on one side of the foundation, this group containing amulticoloured patterned viewing-plate 5, preferable of glass, in theregion of the focal point of the reproducing optical system 2, and alens system 6, arranged behind the viewing plate, sesn in the directionof the beam of light, said system 6 serving to project the beam comingfrom the light-spots on the multicoloured viewing plate on to the screen7. In the embodiments shown in the drawing, the arrangement is suchthat, with the help of the acoustic vibrations to be rendered visible,and through a movable wall influenced by these vibrations, dynamicphenomena are brought about in the transmitting medium, which areobservale in the transmitted light.

The foundation 3 may consist of transparent material, e.g. materialtransmitting percent or more light; it may also however consist ofreflective material, e.g., of material reflecting more than 80 percentof the light striking it. In the former case it may consist of a glassplate, but also for example of a sheet of plastics material, e.g., thematerial known commercially as Hostafan. A condition of satisfactoryoperation according to the invention is that on the one hand it has amaximum diffusion strength, so that it is as impermeable as possible tothe fluid, and on the other hand in certain cases it is very thin, e.g.,15 ,u, as it must, as will be discussed below, pass vibrations on to thetransmitting medium, energising the latter in order to generate the wavemotion. When the foundation is transparent, the abovementioned opticalgroups are located on opposite sides of the foundation; when thefoundation is reflective, both optical groups are on the same side ofthe foundation. A special fluid is preferably used as a transmittingmedium, e.g., a fluorine chemical, preferably the fluid known by thecommercial 'title F C 75, a further condition being that the boilingpoint is relatively high, e.g., at the level of the boiling point ofwater, so that the fluid does not evaporate rapidly, that in additionits viscosity is low, e.g., corresponding to one third of the viscosityof water, so that no wetting additive is needed. It is also necessary tocause or promote the minimum corrosion of the casing.

The foundation 3 for the transmitting medium can be bowlortrough-shaped, the arrangement preferably being such that the bowl ortrough shape becomes shallower from the centre of vibration outwards, inorder to simulate the running of waves on to a shore, and to avoid asfar as possible the occurrence of standing waves. In the embodimentsshown in the drawing, the foundation forms an acute angle with thehorizontal angle, e.g., of up to 10. In any case, the arrangement mustbe such that the free surface of the transmitting medium contained inthe obliquely extending foundation is contained in a horizontal plane,the thickness of the layer of medium resting on the foundationincreasing continuously from one side to the diametrallyopposed side. Inthe variant of the subject-matter of the invention in FIG. 2, the edgeportion (1" of the foundation is not covered by the medium, while thediametrally opposed edge portion b corresponds to the region of greatestthickness of the layer of medium resting on the foundation. Such anarrangement enables quite fantastic effects of-light, form and colour tobe achieved.

The light source 1 can consist ofa so-called Xenon lamp, or of aso-called HBI lamp; a condition of this is that it provides a lightspotof the sharpest contours. In order to determine the effectivecross-section of the beam of light emerging from the light-source, anaperture diaphragm 8 is provided between the light-source and thereproducing optical system 2. Associated with the light-source there isa lens 9 which, seen in the direction of the path of the light 10,consists ofa lens system II on the other side of the light-source, acondenser 12 and a subsequent collector lens 13. Between the reproducingoptical system 2 and the optical system 9 facing the light-source 1,there is provided, seen in the direction of the light and behind thediaphragm, a flat mirror 14 which is directed, for example, at an angleof 45 to the optical axis of optical system 9, and whose purpose is toreflect the beam coming from the light-source on to the reproducingoptical system. The result is that the optical axis of the system 9associated with the light-source forms an angle of 90, with that of thereproducing optical system 2.

The reproducing optical system 2 is so designed that it reproduces theimage at aperture diaphragm 8 on viewing plate 5, which can consist ofglass, in a ratio of 1:1. Optical system 2 is more preferably designedas a so-called schlieren optical system, which contains, coacially toeach other at both outer ends, a plane-concave divergent lens 16a, 16!),between which biconvex collector lenses 17a, 1712 with intense curvatureare provided. The light-source I, the optical system 9 associatedtherewith, the aperture diaphragm 8, the mirror l4 and the opticalsystem 2 are located, in the embodiments shown in the drawing, on theside of the foundation 3 facing away from the transmitting medium 4.

On the side of the foundation facing the transmitting medium there arelocated the viewing plate 5, optical system 6 and screen 7. In this casethe optical axis of optical system 2 and the axis of viewing platecoincide. The viewing plate consists of several parts of differentcolours, preferably three concentric rings 19a, 19b, 190 on differentplanes and which can be moved, e.g., turned, relative to one another.Each ring is subdivided into parts 35, 36, 37, of equal length,succeeding one another along the circumference, which are formed assectors, each part being of a different color from the preceding one.The succeeding parts of the rings can be blue, yellow, red, violet,etc., the colouring of the parts also being different from ring to ring.In

order to turn the rings, a slow-running synchronous induction motor canbe provided, which can operate continuously or imtermittently, and whichcan be in a driving connection with the ring or rings throughintermediate members, e.g., in the form ofa gear system or the like.Each ring can have its own drive motor, or one common motor can beassociated with all of them. The surface of the viewing plate 5 bears agrid, or a network of lines at right angles to one another. The viewingplate is followed by the objective, which throws the images formed on tothe screen.

The wave motions may be generated in various ways. Thus for example thefluid transmitting medium 4 may be energised with the help of thevibrator armature 25 or matrix of a loudspeaker 26, said armaturedipping in the medium, involving to a certain extent in this caseenergisation from above, i.e., from the free surface of the medium.However, the transmitting medium may be energised from below, i.e., fromthe surface in contact with the foundation, to a certain extentinvolving energisation from below. For this purpose a loudspeaker 27 isused, setting the foundation 3 carrying the transmitting medium 4'vibration, in turn energising the transmitting medium itself. Finally,the fluid transmitting medium 4 may also be energised both from the freesurface and from the opposed underside, in order to cause the wavemotion. In this case the fluid transmitting medium 4" is energised onthe one hand on the free surface by the vibrator armature 28 or matrixof the loudspeaker 29, which dips in the medium, and on the other handby causing foundation 3 to vibrate by means of a loudspeaker 30. In allthese cases the loudspeaker is arranged eccentrically relative to thefoundation. Preferably, according to FIG. 2, in the loudspeaker servingto generate the wave motions, the vibrator coil 36, instead of havingthe conventional diaphragm, is connected to a movable wall, e.g., byadhesion, said wall forming part of a cylindrical member 37 made of avery light plastics material which is not soluble in the transmittingmedium, preferably of the plastics material known by the commercialtitle Styropor, said wall preferably forming the end-portion of thiscylindrical member. In the embodiment in FIG. 2 two loudspeakers 38,39are provided to generate the wave motion, both speakers being arrangedeccentrically relative to the foundation and thus being each associatedwith two diametrally opposed points on the circumference of thefoundation or of the medium contained in it, one speaker beingassociated, a highfrequency speaker, with the high-pitched sounds, e.g.,of a frequency from about 5,000 I-Iz up, and the other, as alow-frequency speaker, associated with the lowpitched sounds, in thiscase lying opposite the part of the foundation covered by a thick layerof medium, while the high-frequency speaker is associated with the partof the foundation which is not covered at all, or only by a thin layerof the medium. Both loudspeakers may energise the medium from above, orby direct contact from below, yet the arrangement can be such that onespeaker, e.g., the low-pitch speaker, energises from above, and theother from below. By means of the disposition of the transmitting mediumon the foundation (cf. FIG. 2), and by means of the special method ofenergising the medium, all sounds from a wide range of high and lowfrequencies can be made effective, and every imaginable variation ofsingle and multiple tonescan now be expressed optically. Theenergisation of the transmitting medium generates wave motions, thewaves formed being picked up optically at a point remote from the centreof energisation and close to the energisation point, and are projectedin the transmitted light. Because of the intense dispersion of theradiation speed of the waves, very interesting dynamic images result.

The transmitting medium and the foundation carrying it, and the farthestoptical parts of the device, are enclosed in a casing 31, on one side ofwhich there is located the objective projecting on to the screen, whileon the other side there is the light-source with its associated opticalsystem. I

FIG. 6 shows the electrical part of the device. is the sound source: amagnetic tape, a disc, a microphone (e.g.,-human voice). This soundsource is connected by cables 46a, 46b to the amplifier 47, from whichon the one hand the cables 48a, 48b go to the speakers 49a, 49breproducing the sound waves coming from the sound source (stereoreproduction), and on the other hand the cables a, 5% go to a regulableand adjustable so-called electronic dynamic compressor 51, whose purposeis to smooth out the music to a certain extent, making loud soundsquieter and quiet sounds louder. Part 51 is connected to the amplifier52, to which the low-frequency speaker 53 and the highfrequency speaker541 are connected, serving to energise the medium in the way describedabove. In this way a sound" and a sight branch are to a certain extentestablished, in such a way that regulation and adjustment in accordancewith requirements at any moment can be undertaken independently in bothbranches.

As shown in FIG. 7, in which the parts are given the same referencecharacters as in FIG. 1, but with the subscript a, the foundation 3a isreflective and the whole optical system is on the same side of the base.

1 claim:

1. A device for rendegingrvisibl eacoustic vibrations, in which a fluidtransmittiifg' medium held on a foundation is caused to execute wavemotions with the help of a movable wall or wall section, and in whichthe wave motions thus engendered are rendered optically visible, inwhich on one side of the foundation there is a first optical groupcomprising a light source (1) and a reproducing optical system (2)including means to reproduce a light-spot originating from thelight-source and, on one side of the foundation, a second optical groupcomprising a multicolored patterned viewing plate (5) with a surfacewhich has a grid in the region of the focal point of the reproducingoptical system, and also comprising a lens system (6) arranged behindthe viewing plate when seen in the direction of the beam of light, saidlens system serving to project the beam coming from the light-spot onthe multicolored viewing plate on to a screen (7).

2. A device as in claim 1, in which the foundation has a maximumdiffusion strength, and consists of transparent material, and saidoptical groups are located on opposite sides of the foundation.

3. A device as in claim 1, in which the foundation consists of areflective material and both optical groups are located on the same sideof the foundation.

4. A device as in claim 1, characterised in that the thickness of thelayer of transmitting medium resting on the foundation continuouslyincreases from one side to the diametrally opposed side.

5. A device as in claim 4, characterised in that one edge portion of thefoundation is not covered by the transmitting medium, while thediametrally opposed edge portion corresponds to the region of grestestthickness of the layer of transmitting medium resting on the foundation.

6. A device as in claim 1, in which, in order to determine the effectivecross-section of the beam of light from the light-source (1), anaperture diaphragm (8) is provided between the light-source and thereproducing optical system (2).

7. A device as in claim 1, in which the light-source (1) has associatedwith it an optical system (9) which, seen in the direction of the beamof light (10), consists of a lens system (11) on the same side as thelightsource, a condenser (12) and a subsequent collector lens (13).

8. A device as in claim 7, characterised in that the optical axis of thereproducing optical system (2) forms an angle of with that of theoptical system (9) associated with the light-source.

9. A device as in claim 8, characterised in that there is providedbetween the reproducing optical system (2) and the optical system (9)associated with the lightsource (1) a flat mirror (14), arranged at anangle to the optical axis of said system (9), said mirror reflecting thebeam coming from the light-source in the direction of the reproducingoptical system.

10. A device as in claim 1, in which the reproducing optical system (2)includes means to introduce the image at the aperture diaphragm (8) onthe viewingplate (5) in a raio of 1:1, and comprises an optical systemwhich contains, coaxial to one another, planeconcave divergent lenses(16a, 161)), between which biconvex collector lenses (17a, 171)) withintense curvature are provided.

11. A device as in claim 1, characterised in that the viewing-plate (5)consists of several parts (19a, 19b, 19c) of different colors.

12. A device as in claim 11, characterised in that the viewing-plate (5)is subdivided into sectors succeeding one another along thecircumference, each succeeding sector being of a different color fromthe preceding one.

13. A device as in claim 11, characterised in that the viewing-plate (5)consists of three or more concentric rings (19a, 19b, 19c), said ringsbeing rotatable relative to one another, said viewing-plate (5) beingsubdivided into parts of equal length succeeding one another along thecircumference, each succeeding part being of a different colour from thepreceding one.

1 1. A device as in claim 13, characterised in that, in order to drivethe rings, slow-running synchronous induction motors are provided, whichare in a driving connection with the rings through intermediate members.

15. A device as in claim 1, characterised in that a special fluid isused as a transmitting medium (4), its boiling-point roughlycorresponding to that of water, yet whose viscosity is considerably lessthan that of water.

16. A device as in claim 1, characterised in that the I fluidtransmitting medium (4) is energised, in order to generate the wavemotions.

17. A device as in claim 1, characterised in that the fluid transmittingmedium (4) is energised, in order to generate the wave motions.

18. A device as in claim 1, characterised in that the fluid transmittingmedium (4") is energised on a free surface by the vibrating armature(28) of a loud speaker, dipped in the fluid, and is also energized bycausing the foundation (3' to vibrate by another loudspeaker (30).

19. A device as in claim 17, characterised in that the fluidtransmitting medium (4) is energised with the help of a movable wall ofa loudspeaker in which the vibrator coil is connected, to a movable wallwhich dips into the transmitting medium.

20. A device as in claim 17, characterised in that, in order to generatethe wave motions in the transmitting medium, two loudspeakers arrangedeccentrically to the foundation are used, which are located adjacent twodiametrically opposed points on the circumference of the foundation oneof said speakers, as a so-called high-frequency speaker, beingassociated with a part of the foundation covered in a thick layer of thetransmitting medium, and being associated with the high frequencysounds, and the other, as a so-called lowfrequency loudspeaker, beingassociated with the lower-frequency sounds, and with the part of thefoundation covered at most by a thin layer of the transmitting formspart ofa cylindrical body oflight plastic material.

1. A device for rendering visible acoustic vibrations, in which a fluidtransmitting medium held on a foundation is caused to execute wavemotions with the help of a movable wall or wall section, and in whichthe wave motions thus engendered are rendered optically visible, inwhich on one side of the foundation there is a first optical groupcomprising a lightsource (1) and a reproducing optical system (2)including means to reproduce a light-spot originating from thelight-source and, on one side of the foundation, a second optical groupcomprising a multicolored patterned viewing plate (5) with a surfacewhich has a grid in the region of the focal point of the reproducingoptical system, and also comprising a lens system (6) arranged behindthe viewing plate when seen in the direction of the beam of light, saidlens system serving to project the beam coming from the light-spot onthe multicolored viewing plate on to a screen (7).
 2. A device as inclaim 1, in which the foundation has a maximum diffusion strength, andconsists of transparent material, and said optical groups are located onopposite sides of the foundation.
 3. A device as in claim 1, in whichthe foundation consists of a reflective material and both optical groupsare located on the same side of the foundation.
 4. A device as in claim1, characterised in that the thickness of the layer of transmittingmedium resting on the foundation continuously increases from one side tothe diametrally opposed side.
 5. A device as in claim 4, characterisedin that one edge portion of the foundation is not covered by thetransmitting medium, while the diametrally opposed edge portioncorresponds to the region of grestest thickness of the layer oftransmitting medium resting on the foundation.
 6. A device as in claim1, in which, in order to determine the effective cross-section of thebeam of light from the light-source (1), an aperture diaphragm (8) isprovided between the light-source and the reproducing optical system(2).
 7. A device as in claim 1, in which the light-source (1) hasassociated with it an optical system (9) which, seen in the direction ofthe beam of light (10), consists of a lens system (11) on the same sideas the light-source, a condenser (12) and a subsequent collector lens(13).
 8. A device as in claim 7, characterised in that the optical axisof the reproducing optical system (2) forms an angle of 90* with that ofthe optical system (9) associated with the light-source.
 9. A device asin claim 8, characterised in that there is provided between thereproducing optical system (2) and the optical system (9) associatedwith the light-source (1) a flat mirror (14), arranged at an angle tothe optical axis of said system (9), said mirror reflecting the beamcoming from the light-source in the direction of the reproducing opticalsystem.
 10. A device as in claim 1, in which the reproducing opticalsystem (2) includes means to introduce the image at the apertUrediaphragm (8) on the viewing-plate (5) in a raio of 1:1, and comprisesan optical system which contains, coaxial to one another, plane-concavedivergent lenses (16a, 16b), between which biconvex collector lenses(17a, 17b) with intense curvature are provided.
 11. A device as in claim1, characterised in that the viewing-plate (5) consists of several parts(19a, 19b, 19c) of different colors.
 12. A device as in claim 11,characterised in that the viewing-plate (5) is subdivided into sectorssucceeding one another along the circumference, each succeeding sectorbeing of a different color from the preceding one.
 13. A device as inclaim 11, characterised in that the viewing-plate (5) consists of threeor more concentric rings (19a, 19b, 19c), said rings being rotatablerelative to one another, said viewing-plate (5) being subdivided intoparts of equal length succeeding one another along the circumference,each succeeding part being of a different colour from the preceding one.14. A device as in claim 13, characterised in that, in order to drivethe rings, slow-running synchronous induction motors are provided, whichare in a driving connection with the rings through intermediate members.15. A device as in claim 1, characterised in that a special fluid isused as a transmitting medium (4), its boiling-point roughlycorresponding to that of water, yet whose viscosity is considerably lessthan that of water.
 16. A device as in claim 1, characterised in thatthe fluid transmitting medium (4) is energised, in order to generate thewave motions.
 17. A device as in claim 1, characterised in that thefluid transmitting medium (4) is energised, in order to generate thewave motions.
 18. A device as in claim 1, characterised in that thefluid transmitting medium (4'''') is energised on a free surface by thevibrating armature (28) of a loudspeaker, dipped in the fluid, and isalso energized by causing the foundation (3'''') to vibrate by anotherloudspeaker (30).
 19. A device as in claim 17, characterised in that thefluid transmitting medium (4) is energised with the help of a movablewall of a loudspeaker in which the vibrator coil is connected, to amovable wall which dips into the transmitting medium.
 20. A device as inclaim 17, characterised in that, in order to generate the wave motionsin the transmitting medium, two loudspeakers arranged eccentrically tothe foundation are used, which are located adjacent two diametricallyopposed points on the circumference of the foundation one of saidspeakers, as a so-called high-frequency speaker, being associated with apart of the foundation covered in a thick layer of the transmittingmedium, and being associated with the high-frequency sounds, and theother, as a so-called low-frequency loudspeaker, being associated withthe lower-frequency sounds, and with the part of the foundation coveredat most by a thin layer of the transmitting medium.
 21. A device as inclaim 1, in which the foundation has a thickness of 15 Mu .
 22. A deviceas in claim 11 in which said parts are movable relative to one another.23. A device as in claim 13 in which the rings are on differentsuperposed planes.
 24. A device as in claim 1 in which the fluid mediumhas a vicosity not more than one-third the viscosity of water.
 25. Adevice as in claim 19 in which the movable wall forms part of acylindrical body of light plastic material.